Liu Jingjing, Zhang Zhihui, Yu Zhenglei, Liang Yunhong, Li Xiujuan, Ren Luquan
The Key Laboratory of Engineering Bionic (Ministry of Education, China) and the College of Biological and Agricultural Engineering, Jilin University, 5988 Renmin Street, Changchun, 130025, China.
The Key Laboratory of Engineering Bionic (Ministry of Education, China) and the College of Biological and Agricultural Engineering, Jilin University, 5988 Renmin Street, Changchun, 130025, China; State Key Laboratory of Automotive Simulation and Control, Jilin University, 5988 Renmin Street, Changchun, 130025, China.
Micron. 2018 Jan;104:37-44. doi: 10.1016/j.micron.2017.10.004. Epub 2017 Oct 12.
The Typha leaf, with special multi-level structure, low density and excellent mechanical properties, is an ideal bionic prototype utilized for lightweight design. In order to further study the relationship between the structure and mechanical properties, the three-dimensional macroscopic morphology of Typha leaves was characterized by micro computed tomography (Micro-CT) and its internal microstructure was observed by scanning electron microscopy (SEM). The combination of experimental and computational research was carried out in this paper, to reveal and verify the effect of multi-level structure on the mechanical properties. A universal testing machine and a self-developed mechanical testing apparatus with high precision and low load were used to measure the mechanical properties of the axial compression and lateral bending of the leaves, respectively. Three models with different internal structures were established based on the above-mentioned three-dimensional morphologies. The result demonstrated that the structure of partitions and diaphragms within the Typha leaf could form a reinforcement ribs structure which could provide multiple load paths and make the process of compression and bending difficult. The further nonlinear finite element analysis through LS-DYNA proved that internal structure could improve the ability of the models to resist compression and deformation. The investigation can be the reference for lightweight thin-walled structure design and inspire the application of the bionic structural materials.
香蒲叶具有特殊的多级结构、低密度和优异的力学性能，是用于轻量化设计的理想仿生原型。为了进一步研究结构与力学性能之间的关系，采用微计算机断层扫描（Micro-CT）对香蒲叶的三维宏观形态进行表征，并通过扫描电子显微镜（SEM）观察其内部微观结构。本文开展了实验研究与计算研究相结合的工作，以揭示和验证多级结构对力学性能的影响。分别使用万能试验机和自行研制的高精度低载荷力学测试装置来测量叶片轴向压缩和横向弯曲的力学性能。基于上述三维形态建立了三种具有不同内部结构的模型。结果表明，香蒲叶内部的隔板和横膈膜结构可形成加强肋结构，该结构能提供多条载荷路径并使压缩和弯曲过程变得困难。通过LS-DYNA进行的进一步非线性有限元分析证明，内部结构可提高模型的抗压和抗变形能力。该研究可为轻量化薄壁结构设计提供参考，并激发仿生结构材料的应用。
